4.10 or 4.56 gears

[onebigmj]

I recently bought a 97 cherokee with a 4.0 and a 5speed. I'm going to regear it to either 4.10 or 4.56s with a 32in tire. Would 4.56s be to radical for something that gets driven every day? What rpms would it run in 5th gear at 65mph?

Thanks in advanche for any advice

[LEAD_NOT_FOLLOW]

Use this: http://www.greatlakesxj.com/tech/tech_calcs.html

 

Transmission Gear Ratios

 

Manual Transmissions

AX4 - no information (I assume the same as AX5 minus 5th gear)

T4 - 4.02 | 2.37 | 1.50 | 1.00 | rev?

T5 - 4.02 | 2.37 | 1.50 | 1.00 | 0.76 | rev?

BA10/5 - 3.99 | 2.33 | 1.44 | 1.00 | 0.79 | rev?

AX5 - 3.93 | 2.33 | 1.45 | 1.00 | 0.85 | 4.72(rev)

AX15 - 3.83 | 2.33 | 1.44 | 1.00 | 0.79 | 4.22(rev)

NV3550 - 4.01 | 2.32 | 1.40 | 1.00 | 0.78| 3.55(rev)

 

Automatic Transmissions

TF904 - 2.45 | 1.45 | 1.00 | rev?

30RH - 2.74 | 1.54 | 1.00 | rev?

AW4 - 2.804 | 1.531 | 1.000 | 0.753(OD) | 2.393(rev)

[FxRacing282]

4.10 is plenty. my friend ran 3.11s or something with an auto 4.0 and it would burn the tires all day long on brand new tar with 31's

[Pete M]

Is the rear axle a Dana 35 or an 8.25?

[Eagle]

31 inch tires through 3.73 gears turns EXACTLY the same RPMs as my wife's stock XJ automatic with stock tires and 3.54 gears. If anything, 4.10s would be better for 31 inch tires. 4.10s will be okay for 32s, 4.56 would be better.

 

With 32 inch tires, the RPMs at 65 MPH in overdrive would be 2205 with 4.10s and 2453 with 4.56s. IMHO cruising at 2500 is the sweet spot for those engines. Even 70 MPH will only be 2640 RPM with 4.56s. The engine will run at that speed all year.

[onebigmj]

It has an 8.25 rear axle

[Pete M]

Just checkin'. :D Then it's definitely worth sinking money into.

 

 

And I would go with 4.56.

[onebigmj]

I just bought it for $1500. No rust at all but the drivers side quarter panel needs replaced. 4.0 HO external slave Ax15 8.25. Pretty good combination.

[CWLONGSHOT]

Go 4:56, definitely!!

 

Sticks can really benefit from a ratio on the taller side. Autos are variable anyway, at least until the converter locks up. (If you have a model that does)

 

I have 4:56 on my MJ. I built it around 33" tires. Works great. I really like the ratio. Its still got a good sized pinion, (D30) so there is enough beef. I recently dropped down to a set of MT-R's that are just over 31" tall. (Just a winter tire set) Its even better!!!

I have a TJ with 4:10's rolling on 35's. Its also got a 4:1 Tcase, so off road its geared PLENTY lo. Its also got a number of engine HP upgrades. So it works well with this ratio. BUT I wish I had gone for the taller ratio there as well.

 

Something to ponder, I have never herd anyone swapping gears in a off road vehicle say they wish they hadn't geared it so lo. Have you?

 

CW

[TNT]

I like gearing 4.56 would be my choice for 32"-33" tires.:brows:

 

I'm going with 5.13's and 35"-36" tires.

[hackedmj]

456s, definately with your 5 speed.